Identification of early signs of autism is a critical goal for research. This study will examine fetuses of mothers who have older children with autism spectrum disorder (ASD) in order to identify signs of autism in the prenatal and newborn periods. ASD is highly heritable and there is elevated risk for autism in siblings. Recent research on high-risk infants (those with an older sibling with ASD) has identified potential signs of autism by early infancy. These signs of risk include behavioral features known to be indicative of ASD in later development, including poor social attention, social responsivity, and eye contact. Research from typical and other atypical populations supports the reliable measurement of biobehavioral response profiles in the fetal period. Thus, evidence indicates that it may be possible to identify signs of autism the perinatal and early postnatal periods. Such findings would have profound implications for understanding the developmental course in ASD and would open the door to both identification and treatment in the earliest stages of development. We will investigate fetal movement and heart rate in response to social and non-social stimuli in pregnant mothers who have an older child with an ASD (high risk fetuses) as compared to mothers who have older children with typical development (low risk fetuses). Research has demonstrated that fetal responses to stimuli are predictive of later behavior and temperament, and that fetuses can discriminate familiar voices (i.e., respond differentially to social stimuli). Based on these findings, and utilizing procedures already used in our lab, we will administer vibroacoustic stimulus (vibration plus sound;used regularly in prenatal obstetric care) and a series of social stimuli to the fetus (audio recording of the mother's and a stranger's voice). We will measure fetal responses by observing changes in movement, heart rate, and other signs of reactivity. Measures of neonatal behavior and reactivity will be administered in the newborn period, including analogues to the 3rd trimester stimuli, a newborn neurobehavioral exam, and acoustic cry analyses. Our initial examination of the resulting data will be to compare the response profiles of high and low risk infants. This project will lay the groundwork for developmental follow-up of the at risk infants, and will provide pilot data to support a more extensive study of this kind. PUBLIC HEALTH RELEVANCE: This research is highly relevant to both early identification and intervention for children with autism. By identifying atypical behavioral and reactivity patterns in the fetal and newborn periods in infants at risk for autism, this research will aide in the development of more sensitive and specific screening and diagnostic tools for use in infancy. In addition, this research will improve our understanding of the roots and course of impairments in autism.